Biochemical reactions tables

Electrokinetic Transport with Biochemical Reactions, Table 1 Table of boundary conditions ... 

Special reactors are required to conduct biochemical reactions for the transformation and production of chemical and biological substances involving the use of biocatalysts (enzymes, immobilised enzymes, microorganisms, plant and animal cells). These bioreactors have to be designed so that the enzymes or living organisms can be used under defined, optimal conditions. The bioreactors which are mainly used on laboratory scale and industrially are roller bottles, shake flasks, stirred tanks and bubble columns (see Table 1). 

Table 2 illustrates the effect of the Gibbs free energy on the spontaneity of a chemical/biochemical reaction and the resulting release of energy. Thus, it is useful to use AG values for any biochemical reaction mediated by microbes to determine whether energy is liberated for work, and how much energy is liberated. 

Almost all enzymes are proteins. They provide templates whereby reactants (substrates) can bind and are favorably oriented to react and generate the products. The locations where the substrates bind are known as active sites. Because of the specific 3D structures of the active sites, the functions of enzymes are specific that is, each particular type of enzyme catalyzes specific biochemical reactions. Enzymes speed up reactions, but they are not consumed and do not become part of the products. Enzymes are grouped into six functional classes by the International Union of Biochemists (Table 2.2). 

Hydrolysis is very important in biochemical reactions and refers to a reaction in which a substance reacts with water causing the substance to break into two products. The structure of common table sugar, sucrose, is shown in Figure 16.5. 

Vitamin B12 (cobalamin) serves as a cofactor for several essential biochemical reactions in humans. Deficiency of vitamin B12 leads to megaloblastic anemia (Table 33-2), gastrointestinal symptoms, and neurologic abnormalities. Although... 

Table 10-1 Types of Biochemical Reactions with Ionic Mechanisms... 

OCEAN WATER. An electrolyte solution containing minor amounts of nonelectrolytes and composed predominantly of dissolved chemical species of fourteen elements O, H, Cl, Na. Mg, S, Ca, K, Bl, C, Sr, B, Si, and F (Table 1). The minor elements, those that occur in concentrations of less than 1 ppm by v/eight. although unimportant quantitatively in determining the physical properties of sea water, are reactive and are important in organic and biochemical reactions in the oceans. 

Biomolecules contain a limited number of functional groups that are the reactive centers of the molecules (table 1). Biochemical reactions involving these functional groups are closely related to reactions studied in organic chemistry. Here we describe some of the best known functional groups and the reactions in which they participate. 

It is well known that bile acids are produced in the liver of vertebrates for digestion and absorption of fats and fat-soluble vitamins. Starting from isoprene, a series of biochemical reactions yield a key compound, cholesterol, which is converted to primary bile acids, such as cholic acid (CA), deoxycholic acid (DCA), chenodeoxycholic acid (CDCA) and lithocholic acid (LCA). Hereafter the abbreviations of bile acid derivatives can be seen by consulting Table 1 and Figure 1. 

The relationships between the thermodynamic properties of chemical reactions and the transformed thermodynamic properties of biochemical reactions have been treated in several reviews (Alberty, 1993a, 1994c, 1997b, 2001 e). Recommendations for Nomenclature and Tables in Biochemical Thermodynamics from an IUPAC-IUBMB Committee were published in 1994 and republished in 1996. This report is available on the Web http llwww.chem.qmw.ac.uhlimbmbl thermodl. 

There is a difference between the way these biochemical reactions for glycolysis are written here and in most biochemistry textbooks, which include H + in reactions 1, 3, 6, and 10 and 2H + in the net reaction. These H + are wrong, in principle, because at constant pH, hydrogen atoms in a reaction system are not conserved, and they are stoichiometrically incorrect because integer amounts of hydrogen ions are not consumed or produced, except under special conditions (see Table 4.6). 

A number of biochemical reactions involve proteins as reactants, and so it is important to be able to determine the standard transformed Gibbs energies of formation of their reactive sites at specified pH. The standard transformed Gibbs energies of formation of the active sites of ferredoxin, cytochrome c, and thioredoxin are given in tables discussed earlier in Chapter 4. 

Calorimetric measurements yield enthalpy changes directly, and they also yield information on heat capacities, as indicated by equation 10.4-1. Heat capacity calorimeters can be used to determine Cj , directly. It is almost impossible to determine ArCp° from measurements of apparent equilibrium constants of biochemical reactions because the second derivative of In K is required. Data on heat capacities of species in dilute aqueous solutions is quite limited, although the NBS Tables give this information for most of their entries. Goldberg and Tewari (1989) have summarized some of the literature on molar heat capacities of species of biochemical interest in their survey on carbohydrates and their monophosphates. Table 10.1 give some standard molar heat capacities at 298.15 K and their uncertainties. The changes in heat capacities in some chemical reactions are given in Table 10.2. 

The current table can be considerably extended by use of the compilations of Goldberg and Tewari of evaluated equilibrium data on biochemical reactions (ref. 8). Akers and Goldberg have published "BioEqCalc A Package for Performing Equilibrium Calculations in Biohemical Reactions" (ref. 9). 

---